Re: The Sims 4 won't launch

@RiverKai0402  You'll need to add your mods and custom content back slowly, testing each time to see whether the game still works.  If and when it stops launching again, you'll know that at least one of the files you most recently added is a problem, and you can split that last batch and retest until you find the culprit.  Keep in mind that you may have more than one outdated or corrupt file—just because you find one problem doesn't mean the rest of the mods are fine.